Workflows are models of computation that provide abstractions useful to the scientist conducting e-Science. Workflow practitioners interested in experiment repeatability and large volume data processing must manage both scientific and engineering aspects of workflow development. Engineering concerns are often encapsulated as Workflow Services, though no uniform method of accessing these services exists. A domain-specific software architecture can aid the scientist in accessing these services, isolating the concerns of the engineer from those of scientists through the use of software connectors.